Confirm: Passing QMap reference to helper function edits the same QMap.

main.cpp

#include <QCoreApplication>
#include <QMap>
#include <QMapIterator>
#include <QDebug>

using StringIntMap = QMap<const char*, int>;

void addToMap(StringIntMap &map, const char* key, int value)
{
    map[key] = value;
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    StringIntMap goodmap;
    const char* elsewhere = "elsewhere";
    goodmap[elsewhere] = 50;
    goodmap["justTyped"] = 100;

    addToMap(goodmap, "function1", 200);
    addToMap(goodmap, "function2", 400);

    QMapIterator<const char*, int> iter(goodmap);
    while (iter.hasNext()) {
        iter.next();
        qDebug() << iter.key() << " = " << iter.value();
    }
/* prints:
elsewhere  =  50
justTyped  =  100
function1  =  200
function2  =  400
*/

    return a.exec();
}